The 26-year-old, also known by his comedy stage name of Jonnie Marbles, said outside Westminster Magistrates’ Court: “I would just like to say this has been the most humble day of my life.”
The 80-year-old News Corporation boss used the same words as he began giving evidence at last week’s Commons Culture, Media and Sport Committee hearing into the phone-hacking scandal.
Soon after, May-Bowles, of Edinburgh Gardens, Windsor, Berkshire, disrupted proceedings by launching the foam pie, leaving Mr Murdoch soaking.
His wife, Wendi Deng, leapt to his defence, first pushing May-Bowles away and then throwing the plate at him as he was led off by police.
Yesterday, divorced May-Bowles pleaded guilty to assault and causing harassment, alarm or distress.
He stood in the dock and spoke only to confirm his name, age and address and to admit the charges.
He was supported in court by his father and a group of friends.
Rav Chodha, prosecuting, said that, on July 19, May-Bowles made his way through the Wilson room in Portcullis House to attack Mr Murdoch and used threatening, abusive or insulting words and behaviour.
In a hearing which lasted just 15 minutes, the prosecutor added that Mr Murdoch did not support the charge of assault.
The case was adjourned for pre-sentencing reports until Tuesday August 2 when May-Bowles will return to court to be sentenced.
His solicitor, Raj Chada, asked District Judge Daphne Wickham for another date because May-Bowles had booked a holiday with his family and young son. But Mrs Wickham was unmoved and said a warrant would be issued for his arrest if he did not turn up.
“He is on bail for a serious offence which carries a risk of imprisonment,” she said.
“It’s due process.
“He should have thought about this on the 19th of July when he committed these offences.”